EBV nucleic acids and antigens are commonly detected in association with the tumor cells of Hodgkin's disease. Abnormal immune function has long been recognized in patients with Hodgkin's disease but there has not yet been any systematic attempt to study EBV infection and the immune response to EBV in patients with Hodgkin's disease. We will study patients with newly diagnosed EBV(+) and EBV(-) Hodgkin's disease seen at the Joint Center for Radiation Therapy in Boston to determine: (i) the EBV load in peripheral blood lymphocytes, (ii) the CD8 cytotoxic immune response to a panel of EBV latency antigens expressed in Hodgkin's disease, (iii) the CD4 proliferative and cytokine responses to a panel of EBV latency antigens. This study will be the first comprehensive study of EBV and Hodgkin's disease, and will provide information crucial to characterizing the interplay between the viral infection, the immune system and tumorigenesis.